“Fueling the dropping unemployment rate has been strong employment growth, which has outpaced national employment growth for what is expected to be five out of the last seven years,” said Ryan M. Brewer, associate professor of finance at Indiana University-Purdue University Columbus and author of the forecast. “Attracting new opportunities for additional job growth becomes more difficult as the labor market tightens further.”

Job growth in the U.S. exceeded economists' expectations this year and is likely to continue into 2018, economists say.

Part of the growth in both the U.S. and Indiana can be attributed to future hurricane recovery in Texas and Florida as people replace vehicles that were destroyed, said Timothy Slaper, research director of the Indiana Business Research Center.

The report also singles out a nontraditional threat to future economic growth in Indiana: the opioid epidemic.

Brewer said Indiana could lose between $1.25 billion to $1.8 billion annually in gross state product from those addicted to opioids in the state.

“Indiana employers are having difficulty finding workers quickly enough to support full economic growth," Brewer said. "Opioids and amphetamines exacerbate this problem.”